The utility of compact backshell/wiring integration and interface systems to replace bulky wiring harness connectors for interconnecting individual conductor wires in the wiring harness to other units has been described in U.S. Pat. Nos. 5,244,417; 5,308,264; and 5,342,203, all granted to F. A. Perretta, et al., and all assigned to United Technologies Corporation. These interface systems utilize one or more semi-flexible circuit boards which are disposed in an EMI-shielding housing and are operable to shield the conductor wire connections from ambient EMI. These references describe a conductor ground ring which provides a minimal inter-conductor unshielded window within the backshell housing. Signal leakage from the individual conductors is minimized, but can still occur in the unshielded conductor segments between the stripped shielding and the ground ring. Signal leakage can also occur from the bare ends of the conductor wires where they protrude from the circuit boards at the board/wire connections. Thus, potentially undesirable amounts of signal leakage can occur within the shielded interface housing. The aforesaid patents, particularly the U.S. Pat. No. 5,342,203, describe the use of filter capacitors mounted on the circuit board and operable to filter out inter-conductor signal cross talk which might otherwise occur between high and low frequency signal conductor paths within the circuit board. The aforesaid structure minimizes inter-conductor signal path cross talk within the circuit board, but does not address all interconductor cross talk, such as pre-circuit board cross talk between stripped conductor wires within the shielded interface housing. From the aforesaid, it will be noted that incremental, yet potentially important, signal leakage and/or cross talk can occur within the interface housing. It would be desirable to provide a wire harness interface housing assembly which would completely eliminate signal leakage within the housing assembly, as well as eliminate interconductor wire signal cross talk within the housing assembly.